Medical delivery devices such as syringes, auto-injectors, and pens typically include a barrel, a stopper positioned within the barrel, and a plunger rod or actuation mechanism to displace the stopper. The stopper is typically air and liquid impermeable while also possessing low-friction slidability. Air and liquid impermeability is important for eliminating liquid leakage within the barrel and the introduction of air between an outer face of the stopper and an inner wall of the barrel when charging or discharging the liquid inside the medical delivery device. Low-friction slidability is important for facilitating the charging and discharging of the liquid inside the medical delivery device. In addition to these requirements, a medical syringe, auto-injector, or pen should not adversely affect any pharmaceutical composition such as biopharmaceuticals that come in contact with the syringe (e.g., a pre-filled syringe, auto-injector, or pen comprising a pharmaceutical composition).
Accordingly, a need exists for stoppers covered with a fluoropolymer or non-fluoropolymer film or laminate that when used in conjunction with hydrophilic glass or resin barrels are able to achieve high levels of air and liquid impermeability while also achieving a low average glide force and low glide force variation.